Diesels and Automatic Gearboxes

DRZ · 17 Jul 2015 at 18:23

Scania said:
No, it was "plucked" from the chap who changed my ATF fluid about three months back.

It was black and treacle like on removal, he wasn't surprised to see it like this, the car has done nearly double the 60k figure he mentioned.

The box is much smoother now and the gearbox warning light (yellow cog) has not come back on since.

Presumably I should have not touched it because its sealed for life and awaited the boxes demise?

Black like treacle? My completely ****** Audi S6's box had burned its fluid slightly and that was something like 130k when that happened, and that was still red(ish).

For it to be black, either it was black when it went in or you've got a gearbox issue/you're doing things to overheat your gearbox oil significantly (towing heavy things up steep hills regularly etc)

The reason engine oil goes black over time is because carbon and other nasty stuff is deposited in the oil, not because it is worn.

slick rick · 17 Jul 2015 at 18:31

My ATF was black also. I assume it was the original fluid and had done 140k.

Jokester · 17 Jul 2015 at 18:35

Just had the oil changed in my S-Tronic as per the service schedule (40k miles). Can tell the difference!

Dangerous Dave · 17 Jul 2015 at 18:41

I recently changed the oil in my manual box and the old oil was black and like treacle at 106k. I was surprised how bad it was so ran the new oil for 1k and changed it again, the gear change was noticeably better after the first change.

slick rick · 17 Jul 2015 at 18:50

Dangerous Dave said:
I recently changed the oil in my manual box and the old oil was black and like treacle at 106k. I was surprised how bad it was so ran the new oil for 1k and changed it again, the gear change was noticeably better after the first change.

I intended to replace the filter and fluid after 1k, but the price of the fluid just put me off TBH. I have done over 6/7k since replacing it and its been fine (touch wood).

Bradmax57 · 17 Jul 2015 at 18:51

Guess I should consider getting my "just" sub 100k 330d done

Scania · 18 Jul 2015 at 10:53

DRZ said:
Black like treacle? My completely ****** Audi S6's box had burned its fluid slightly and that was something like 130k when that happened, and that was still red(ish).

For it to be black, either it was black when it went in or you've got a gearbox issue/you're doing things to overheat your gearbox oil significantly (towing heavy things up steep hills regularly etc)

The reason engine oil goes black over time is because carbon and other nasty stuff is deposited in the oil, not because it is worn.

I was a bit concerned about the state of the fluid tbh, it looked awful!

The cars not had a towbar previously although part of the reason for changing the fluid is because I'm having a towbar fitted next week ready to tow my caravan.....

I'm hoping whatever the issue was is gone now since the change, the box feels like a new one and is much smoother and quicker changing up and down...

I reckon the caravan tow will be the test, I hope it manages!

cuke2u · 18 Jul 2015 at 17:58

There is a difference between automatic and dsg boxes, not sure if whether the clutches are wet or dry also make a difference on dsg ones as well...

smr · 20 Jul 2015 at 14:18

I'm going to look at Diesel S-Max Auto on Wednesday, I have read up on DPFs extensively and figured that my driving habits will actually be ok for them. I live very close to the M1 and long A roads (A46 if anyone knows it) and do regular enough 20-30 minute journeys.

pepsilol · 20 Jul 2015 at 16:05

slick rick said:
I intended to replace the filter and fluid after 1k, but the price of the fluid just put me off TBH. I have done over 6/7k since replacing it and its been fine (touch wood).

Eh, which model and year vehicle do you have where the fluid is that expensive ?

acemastr · 20 Jul 2015 at 16:28

Am I right in saying that people have issues with changing fluid in slushboxes (BMW specifically) in that they generally work well, or they die soon after?